Gartland Classification of Pediatric Supracondylar Humerus Fractures
The Gartland classification system divides extension-type supracondylar humerus fractures into three main types based on displacement and cortical integrity, with Type II further subdivided in the modified system 1.
Classification System
Type I: Nondisplaced or minimally displaced fractures
- Anterior humeral line passes through the capitellum
- Posterior cortex remains intact
- No angulation or rotation
- May have only a posterior fat pad sign visible on radiograph
Type II: Displaced fractures with intact posterior cortex
- Anterior humeral line does not intersect the capitellum
- Posterior cortex remains intact (hinged)
- Visible angulation or rotation present
- Modified Gartland subdivides Type II:
- Type IIA: Intact medial column, angulation only
- Type IIB: Medial comminution present, rotational instability
Type III: Completely displaced fractures
- Complete disruption of both anterior and posterior cortices
- No cortical contact between fracture fragments
- Periosteum disrupted on both sides
- Highest risk for neurovascular complications
Clinical Relevance to Treatment
The classification directly determines treatment approach 1:
- Type I: Nonsurgical immobilization with posterior splint or cast (Moderate recommendation)
- Type II and III: Closed reduction with percutaneous pin fixation (Moderate recommendation)
- The distinction between Type IIA and IIB remains controversial, with only 57.9% of surveyed pediatric orthopedists deeming this subclassification necessary for treatment decisions 2
Reliability of the System
The Gartland classification demonstrates substantial interobserver reliability with kappa values ranging from 0.68-0.85 across multiple studies 3, 4, 5, 6. Agreement is highest for Type III fractures (full agreement) and moderate for distinguishing Type I from Type II 3. The most common disagreement occurs between Type II and Type III classifications, particularly when radiologists classify as Type II and orthopedic surgeons classify as Type III 5.
Important Caveats
Flexion-type supracondylar fractures represent a distinct entity but are grouped with extension-type fractures in treatment recommendations 1. These have an 80% open reduction rate and should be anticipated as high-risk for failed closed reduction 7.
Gartland Type IV (multidirectional instability confirmed intraoperatively) is not part of the original classification but represents fractures with instability in both flexion and extension, strongly associated with need for open reduction (OR 5.21) 7.
The classification system's moderate interobserver agreement suggests that treatment variability for Type II fractures may reflect surgeon preference differences rather than classification inconsistency 6.